1. Field of the Invention
The present invention relates to a transformer used in a power supply device of a variety of electronic products, and more particularly to an apparatus for fixing a bobbin to a printed circuit board for use in a transformer, by which the transformer becomes slim in its installation height when the transformer is installed on the printed circuit board. The present invention is based on Korean Patent Application No. 2002-47137, which is incorporated herein by reference.
2. Description of the Prior Art
As shown in FIG. 1, a transformer 1 is generally comprised of a bobbin 2 and an E-type core 5. Around an upper portion of the bobbin 2 is wound a coil 3, and at a lower portion of the bobbin 2 are provided a plurality of lead pins 7 connected to an end of the coil 3 and a protruding support portion 6 for supporting the lead pins 7 to space the lead pins 7 apart from a printed circuit board 4 by a predetermined distance. The core 5 is inserted into a middle of the bobbin 2 around which the coil 3 is wound.
The lead pins 7 protruding downward from the bobbin 2 are inserted and soldered into fixing openings 4a formed in the printed circuit board 4 that is employed in an electronic product such as a TV, a monitor, and the like.
Accordingly, when the transformer 1 operates and generates a voltage in the coil 3 wound around the upper portion of the bobbin 2, the generated voltage is supplied to the electronic product such as the TV, the monitor and the like connected to the printed circuit board 4 through the lead pins 7.
The transformer 1, however, is structured in a manner that the lead pins 7 of the bobbin 2 are supported on the protruding support portion 6, while being spaced apart from the printed circuit board 4 by the predetermined distance, and thus has a problem that an installation height of the transformer 1 is higher as much as the height of the protruding support portion 6.
As the installation height of the transformer 1 becomes higher, the electronic product becomes thicker. Therefore, there is a problem of inconvenience in use.
In order to prevent the installation height of the transformer 1 from becoming higher, the use of a surface mount device (SMD) type transformer can be considered. However, the SMD type transformer deteriorates work efficiency and thus increases a probability of inferior product, and also has a restriction of voltage capacity and thus cannot be applied in an apparatus of high capacity.